1. Field of the Invention
The present invention relates to a printer and a method for printing.
2. Discussion of the Background
In case of a large-scale inkjet printer or the like, printing is often conducted during hours without operator, such as at night, because it takes time to form entire image. In this case, however, if the remaining amount of ink in an ink cartridge is small, the ink may be finished up (this phenomenon will be referred to as “ink end”) during the image formation so that the printing is interrupted.
The ink end during the image formation can be avoided by replacing such an ink cartridge with a new ink cartridge before printing, for example. In this case, however, there is a problem that the amount of ink to be disposed is increased because the cartridge replaced has still remaining ink.
For solving this problem, a method has been conventionally proposed in which a plurality of ink cartridges for ink of same color are used and are adapted to be automatically switched (for example, Japanese Unexamined Patent Application Publication 2004-098365 A). This arrangement enables ink of the respective ink cartridges to be sequentially finished up while preventing the ink end during image formation. The contents of JP 2004-098365 A are incorporated herein by reference in their entirety.
In the printer disclosed in JP 2004-098365 A for example, however, it is required to prepare ink supply mechanisms of which number is an integral multiple of the number of colors of inks to be used. As a result, problems of increase in apparatus size, increase in cost, and the like must arise. Accordingly, the method of automatically switching ink cartridges is hardly employed in a printer which is intended to be produced at low cost.